@@ -8,6 +8,7 @@
#include <xen/livepatch.h>
#include <xen/vmap.h>
+#include <asm/cpufeature.h>
#include <asm/livepatch.h>
#include <asm/mm.h>
@@ -175,6 +176,8 @@ void __init arch_livepatch_init(void)
end = (void *)LIVEPATCH_VMAP_END;
vm_init_type(VMAP_XEN, start, end);
+
+ cpus_set_cap(LIVEPATCH_FEATURE);
}
/*
@@ -165,6 +165,8 @@ static inline int apply_alternatives(void *start, size_t lenght)
return 0;
}
+#define ALTERNATIVE(oldinstr, newinstr, ...) ""
+
#endif
#endif /* __ASM_ALTERNATIVE_H */
@@ -40,7 +40,12 @@
#define ARM32_WORKAROUND_766422 2
#define ARM64_WORKAROUND_834220 3
+#ifdef CONFIG_LIVEPATCH
+#define LIVEPATCH_FEATURE 4
+#define ARM_NCAPS 5
+#else
#define ARM_NCAPS 4
+#endif
#ifndef __ASSEMBLY__
@@ -34,6 +34,7 @@ XEN_CPUFEATURE(MFENCE_RDTSC, (FSCAPINTS+0)*32+ 9) /* MFENCE synchronizes RDTS
/* An alias of a feature we know is always going to be present. */
#define X86_FEATURE_ALWAYS X86_FEATURE_LM
+#define LIVEPATCH_FEATURE X86_FEATURE_ALWAYS
#if !defined(__ASSEMBLY__) && !defined(X86_FEATURES_ONLY)
#include <xen/bitops.h>
@@ -20,7 +20,6 @@ const char *xen_hello_world(void)
unsigned long tmp;
int rc;
- alternative(ASM_NOP8, ASM_NOP1, X86_FEATURE_LM);
/*
* Any BUG, or WARN_ON will contain symbol and payload name. Furthermore
* exceptions will be caught and processed properly.
@@ -28,8 +27,11 @@ const char *xen_hello_world(void)
rc = __get_user(tmp, non_canonical_addr);
BUG_ON(rc != -EFAULT);
#endif
-#ifdef CONFIG_ARM_64
- asm(ALTERNATIVE("nop", "nop", ARM64_WORKAROUND_CLEAN_CACHE));
+#ifdef CONFIG_ARM
+ asm(ALTERNATIVE("nop", "nop", LIVEPATCH_FEATURE));
+#endif
+#ifdef CONFIG_X86
+ asm(ALTERNATIVE(ASM_NOP8, ASM_NOP1, LIVEPATCH_FEATURE));
#endif
return "Hello World";
}
To use as a common way of testing alternative patching for livepatches. Both architectures have this FEATURE and the test-cases can piggyback on that. Suggested-by: Julien Grall <julien.grall@arm.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> --- Cc: Julien Grall <julien.grall@arm.com> Cc: Stefano Stabellini <sstabellini@kernel.org> Cc: Jan Beulich <jbeulich@suse.com> Cc: Andrew Cooper <andrew.cooper3@citrix.com> v3: New submission --- xen/arch/arm/livepatch.c | 3 +++ xen/include/asm-arm/alternative.h | 2 ++ xen/include/asm-arm/cpufeature.h | 5 +++++ xen/include/asm-x86/cpufeature.h | 1 + xen/test/livepatch/xen_hello_world_func.c | 8 +++++--- 5 files changed, 16 insertions(+), 3 deletions(-)